1. Field of the Invention
The present invention relates to a display system for displaying multimedia document information containing a character, a graph, a picture image and the like (hereinafter simply referred to as "document information") on a display device, and more particularly to a display system suited for interactive document processing.
2. Description of the Prior Art
A conventional multimedia display system includes an image memory having a storage capacity corresponding to one page of a document, and the whole information, including characters, graphs and picture images written on one page, is stored in the image memory in the form of dot information. When characters, a graph and a picture image in a rectangular region (namely, a window) are to be displayed, dot information in the region is taken out of the image memory, and is transferred to a bit-map memory.
In the above system, the image memory is required to have a storage capacity of about 500 KB in order to be able to store therein information on one page of size A4, or to have a storage capacity of about 1 MB in order to be able to store therein information on one page of size A3. That is, an expensive memory is required.